The present invention relates to a device for measuring the elasticity of red blood corpuscles (Erythrocytes). Red blood corpuscles are stored under sterile conditions in plastic bags together with nutrient such as SAG-M solution. In the case at certain conditions of disease red blood corpuscles only have to be injected, and to enable injection the quality of the red blood corpuscles must be known. Hitherto no means has been available for determining the elasticity of the red blood corpuscles and it has just been assumed that after a certain period of storage the red blood corpuscles cannot be used for injection purposes and must therefore be rejected. It is normally assumed that red blood corpuscles can be stored for about 60 days at a storage temperature of between 4 end 6xc2x0 C. Initially the red blood corpuscles are elastic and mouldable but become gradually stiffer with time, which means that when the elasticity has fallen to a certain level the rod blood corpuscles can no longer be injected since this would cause problems in conjunction with injection.
The object of the present invention is to provide a device with the aid of which it is possible to determine the elasticity of the red blood corpuscles so that the lowest tolerable elasticity can immediately be determined. For this purpose two surfaces are used which can be moved towards and away from each other, one of the surfaces being stationary while the other can be moved towards or away from the lower surface. A package, e.g. a plastic bag, containing red blood corpuscles and nutrient, the contents being sterile, is placed between the two surfaces. The movable surface is subjected to a pressure applied thereon so that the surface is continuously under a predetermined pressure. The weighted surface is subjected to extra pressure pulses with intervals between, whereupon the time is measured for the cell to resume the shape it had prior to a pressure pulse. This measuring procedure can be repeated and transferred to a computer, with the aid of which information is available as to whether the contents of the bag being tested is suitable for injecting or not. It has proved suitable for the two surfaces to be in the shape of a rectangular plates, one plate being movable and the other stationary, the ends of the plates being pivotably joined together by means of a suitable hinge construction. The point of pivot is suitably arranged at a distance from a support surface, whereas the other and of the lower plate abuts the support surface. A suitable angle for the lower plate in relation to the support surface is in the order of 45xc2x0. With this arrangement also the bag is placed between the plates and the upper plate is subjected to pressure. In this case no distance can be measured between the two plates and instead the angle prevailing when the red blood corpuscles have been compressed as far as possible is measured. After which the time is measured from when a pulse ceases to when the red blood corpuscles resume their normal shape. The frequency of the pressure and variations in the angle are transferred to a control station which records the necessary data to be able to reach an assessment of whether the red blood corpuscles in the blood bag are injectable or not.